amino acid

noun

: an amphoteric organic acid containing the amino group NH₂

especially : any of the various amino acids having the amino group in the alpha position that are the chief components of proteins and are synthesized by living cells or are obtained as essential components of the diet

Examples of amino acid in a Sentence

Recent Examples on the Web

Diving deeper, the researchers found that the reason the western plants were pumping out an ancient mix of alkaloids had to do with a change to four amino acids in one of the plants' enzymes. —New Atlas, 29 June 2025

Taurine is an abundant amino acid and a key ingredient in energy drinks like Red Bull. —Tom Chivers, semafor.com, 10 June 2025

When protein is properly digested, it’s converted into amino acids and peptides, whereas undigested proteins can alter the intestinal environment. —Misaki Kawatsu, Vogue, 10 June 2025

Fueled by social media, more boys and men are turning to supplements like amino acids, creatine monohydrate, pre-workout drinks or powders, protein bars and whey protein product in an effort to bulk up and look like their cartoon superhero. —Scott Lafee, San Diego Union-Tribune, 3 June 2025

Word History

First Known Use

1897, in the meaning defined above

Rhymes for amino acid

• antacid
• placid

Kids Definition

amino acid

noun

ami·​no acid

ə-ˈmē-nō-

: any of numerous acids that include some which are the building blocks of proteins and are made by living cells from simpler compounds or are obtained in the diet

Medical Definition

amino acid

noun

: an amphoteric organic acid containing the amino group NH₂

especially : alpha-amino acid